Slip of grip of a molecular motor on a crowded track: Modeling shift of reading frame of ribosome on RNA template

We develop a stochastic model for the programmed frameshift of ribosomes synthesizing a protein while moving along a mRNA template. Normally the reading frame of a ribosome decodes successive triplets of nucleotides on the mRNA in a step-by-step manner. We focus on the programmed shift of the ribosomal reading frame, forward or backward, by only one nucleotide which results in a fusion protein; it occurs when a ribosome temporarily loses its grip to its mRNA track. Special "slippery" sequences of nucleotides and also downstream secondary structures of the mRNA strand are believed to play key roles in programmed frameshift. Here we explore the role of an hitherto neglected parameter in regulating -1 programmed frameshift. Specifically, we demonstrate that the frameshift frequency can be strongly regulated also by the density of the ribosomes, all of which are engaged in simultaneous translation of the same mRNA, at and around the slippery sequence. Monte Carlo simulations support the analytical predictions obtained from a mean-field analysis of the stochastic dynamics.Comment: This is an author-created, un-copyedited final version of an article published in EP

Study of young stellar objects and associated filamentary structures in the inner Galaxy

Young Stellar Objects (YSOs) in the inner Galactic region $10^0 < l < 15^0$ and $-1^0 < b < 1^0$ are studied using GLIMPSE images and GLIMPSE data catalogue. A total number of 1107 Class I and 1566 Class II sources are identified in this Galactic region. With the help of GLIMPSE 5.8 $\mu$m & 8 $\mu$m images, we have identified the presence of 10 major star forming sites in the Galactic midplane, of which 8 of them are filamentary while 2 are possible clusters of Class I & II sources. The length of the identified filaments are estimated as 8'-33' ($\sim$ 9 - 56 pc). Occurrence of Hub-Filamentary System (HFS) is observed in many filamentary star forming sites. Most of the Class I sources are found to be aligned along the length of these filamentary structures, while Class II sources have a random distribution. Mass and age distribution of 425 Class I and 241 Class II sources associated with filaments & clusters are studied through their SED analysis. Most of the Class I sources detected have mass $>$ 8M$_\odot$, while Class II sources have relatively low mass regime. Class I sources have ages $\le$ 0.5 Myr, while Class II sources have ages in the range $\sim$0.1 - 3 Myr. Along with the help of high mass star forming tracers, we demonstrate that the 10 regions studied here are forming a large number of high-mass stars.Comment: 19 pages, 18 figures. Accepted for publication in MNRA

Beyond English : translating modernism in the global south

textMy title echoes Agha Shahid Ali’s sentiment of needing to move beyond the linguistic nationalism of “English” toward a more varied understanding of Anglophone writing within multiple contexts in the world. In three theoretical case studies from four linguistic and literary traditions (English, Bengali, Spanish, and Hindi-Urdu), I explore the dimensions and definitions of comparative Anglophone and world literature, comparative poetics, and a comparative study of novels – in the global postcolonial world. I focus on moments of translatability and untranslatability to question traditional models for studies in English and comparative literature that do not account for translation. Each of my chapters shows how texts in the “original” or “translation” do not always circulate from a homogenized metropolitan center to a marginalized periphery, and unlike in the elite North American and Parisian world where untranslatability often inspires terror and loss of language, translations can act as connecting forces that create organic dialogue in the global south on modernism and postcolonial discourses that go beyond Europe and AmericaComparative Literatur